Dear colleagues, We are happy to announce that the lectures of the first week of the thematic trimester « Semantics of Proofs and Certified Mathematics » are available online on the channel of the Institut Henri Poincaré: https://www.youtube.com/watch?v=ONs_6TPe1bE&list=PL9kd4mpdvWcCUOrG5S7KrvOFDhyqnXoUj Besides the keynote talks given during the kick-off meeting of the trimester: Georges GONTHIER (Microsoft Research, Cambridge, and MSR-INRIA Joint Centre, Palaiseau) Thomas HALES (University of Pittsburgh) Xavier LEROY (INRIA Paris - Rocquencourt) Vladimir VOEVODSKY (Institute for Advanced Study, Princeton) two mini-courses of three hours each by Gérard BERRY (Collège de France) Jean-Yves GIRARD (CNRS, Institut de Mathématiques de Luminy) Hope that you enjoy the recordings, The organizers, Pierre-Louis Curien <curien@pps.univ-paris-diderot.fr> Hugo Herbelin <herbelin@inria.fr> Paul-André Melliès <mellies@pps.univ-paris-diderot.fr> [For admin and other information see: http://www.mta.ca/~cat-dist/ ]